Chronic pancreatitis is usually characterized by a progressive loss of pancreatic parenchymal tissue. In many individuals, chronic pancreatitis is clinically silent. Further, many patients with unexplained abdominal pain may actually have chronic pancreatitis that eludes diagnosis. Chronic pancreatitis is associated with a mortality rate that approaches 50 percent within 20 to 25 years. Approximately 15 to 20 percent of patients die of complications associated with attacks of pancreatitis. It has recently been reported that pancreatic cancer develops in approximately 4 percent of patients within 20 years of a diagnosis of chronic pancreatitis.
With the rapid evolution of pancreatic imaging over the last two decades, computerized tomography and endoscopic retrograde pancreatography (ERP) have become invaluable tools in the evaluation and management of pancreatic disorders. Nevertheless, chronic pancreatitis has been reported in up to 24% of patients having a negative diagnosis with these non-invasive techniques.
Direct invasive pancreatic function testing plays an important role in the diagnosis of abdominal pain of unclear etiology, especially when pancreatic disease is suspected in spite of negative imaging tests. Conventional invasive techniques for pancreatic juice collection used to supplement or replace the above imaging techniques include the secretin-pancreozymin test as well as the intraductal sampling technique.
The secretin-pancreozymin test involves the collection of duodenal fluid and the measurement of various characteristics after the inducement of pancreatic functions. Although the secretin-pancreozymin test has been shown to have a sensitivity and specificity in the 90% range, its use in the United States has been limited to few specialized centers. This is due to its complexity and cumbersome nature, resulting in the inability to successfully pass a Dreiling.TM. catheter into the duodenum of approximately 20-50% of the patients. This degree of difficulty increases the cost of the procedure by requiring the administration by trained technicians. Furthermore, the time involved to pass the catheter into the duodenum on the remaining 50-80% of the patients takes from 0.5 to 2 hours. In addition, the discomfort experienced by the patient narrows the applicable use of the technique to only those extreme conditions where its use is essential. This is particularly true in patients having motility disorders of the gastrointestinal (GI) tract, which is seen in up to 20% of those referred for testing.
In the intraductal sampling technique, pure pancreatic juice is collected using a 1.5 mm catheter placed into the pancreatic duct by gastroenterologic procedures (ERP). Although this technique has been shown to yield similar results to the secretin-pancreozymin test, it requires a highly skilled endoscopist because it requires the selective localization of the main pancreatic duct, followed by deep cannulation and placement of a collection catheter deep within the pancreatic duct. Furthermore, this process has the risks inherent to an ERP.
Thus, it has been determined that chronic pancreatitis can be difficult to diagnose, especially in the initial three to five years of disease. As a result, most patients undergo repeated testing which usually includes multiple imaging and invasive evaluations.
What is needed, therefore, is a method for obtaining pancreatic juice that does not require an experienced technician to administer, and which can be successfully administered quickly and cost effectively, regardless of GI motility. Furthermore, the method must not cause significant patient discomfort to reduce patient resistance to the technique.